1. Field of the Invention
The invention relates to a rolling bearing.
2. Description of the Related Art
Many rolling bearings are used for various types of industrial equipment. A rolling bearing includes an inner ring, an outer ring, a plurality of rolling elements, and a cage. The rolling elements are interposed between the inner ring and the outer ring. The cage holds the rolling elements. For example, in each rolling bearing 90 that supports a rotating shaft 95 in a housing 97, an inner ring 91 is fitted over and attached to the rotating shaft 95, and an outer ring 92 is attached to an inner peripheral surface 98 of the housing 97, as depicted in FIG. 10.
In particular, when the rolling bearing 90 is a deep groove ball bearing and is subjected to an axial load in one direction, the inner ring 91 and the rotating shaft 95 are assembled in a “interference fit” state. In contrast, the outer ring 92 and the housing 97 are often assembled in a “clearance fit” state. Thus, in a use state where the rotating shaft 95 is rotating, creep (slip of the outer ring 92 with respect to the housing 97 in a circumferential direction) is likely to occur between the outer ring 92 and the housing 97.
Thus, a rolling bearing has been proposed in which a groove (annular groove) is formed in an outer peripheral surface 92b of the outer ring 92 to suppress possible creep (see Japanese Patent Application Publication No. 2006-322579 (JP 2006-322579 A)). This rolling bearing 90 enables suppression of creep that is likely to occur when a heavy load is imposed on the bearing in a radial direction. The creep that is likely to occur when such a load is imposed on the bearing causes the outer ring 92 to slip slowly in the same direction as a rotating direction of the bearing.
As described above, the annular groove 93 formed in the outer peripheral surface 92b of the outer ring 92 enables the above-described creep to be suppressed if a heavy load is imposed on the rolling bearing in the radial direction. However, the heavy radial load causes corners 99 of the annular groove 93, which face each other in the axial direction, to come into contact with the housing 97. This leads to a local increase in a contact surface pressure on portions of the housing 97 that are contacted by the corners 99. In this case, even slight creep of the outer ring 92 makes wear of the housing 97 likely to progress.